// Berkeley Open Infrastructure for Network Computing
// http://boinc.berkeley.edu
// Copyright (C) 2006 University of California
//
// This is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation;
// either version 2.1 of the License, or (at your option) any later version.
//
// This software is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// See the GNU Lesser General Public License for more details.
//
// To view the GNU Lesser General Public License visit
// http://www.gnu.org/copyleft/lesser.html
// or write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


#include "config.h"
#include <stdio.h>

#include <ctype.h>
#include <sys/types.h>
#include <dirent.h>

#include "procinfo.h"
#include "client_msgs.h"

using std::vector;


// see:
// man 5 proc
// /usr/src/linux/fs/proc/array.C

struct PROC_STAT {
    int pid;
    char comm[256];
    char state;
    int ppid;
    int pgrp;
    int session;
    int tty_nr;
    int tpgid;
    unsigned long flags;
    unsigned long minflt;
    unsigned long cminflt;
    unsigned long majflt;
    unsigned long cmajflt;
    unsigned long utime;
    unsigned long stime;
    int cutime;
    int cstime;
    int priority;
    int nice;
    int zero;
    int itrealvalue;
    unsigned long starttime;
    unsigned long vsize;
    int rss;
    unsigned long rlim;
    unsigned long startcode;
    unsigned long endcode;
    unsigned long startstack;
    unsigned long kstkesp;
    unsigned long kstkeip;
    unsigned long signal;
    unsigned long blocked;
    unsigned long sigignore;
    unsigned long sigcatch;
    unsigned long wchan;
    unsigned long nswap;
    unsigned long cnswap;
    int exit_signal;
    int processor;

    int parse(char*);
};

int PROC_STAT::parse(char* buf) {
    int n = sscanf(buf, "%d %s %c %d %d %d %d %d "
"%lu %lu %lu %lu %lu %lu %lu "
"%ld %ld %ld %ld %ld %ld "
"%lu %lu "
"%ld "
"%lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu "
"%d %d",
        &pid,
        &comm,
        &state,
        &ppid,
        &pgrp,
        &session,
        &tty_nr,
        &tpgid,
        &flags,
        &minflt,
        &cminflt,
        &majflt,
        &cmajflt,
        &utime,
        &stime,
        &cutime,
        &cstime,
        &priority,
        &nice,
        &zero,
        &itrealvalue,
        &starttime,
        &vsize,
        &rss,
        &rlim,
        &startcode,
        &endcode,
        &startstack,
        &kstkesp,
        &kstkeip,
        &signal,
        &blocked,
        &sigignore,
        &sigcatch,
        &wchan,
        &nswap,
        &cnswap,
        &exit_signal,
        &processor
    );
    return 0;
}

// build table of all processes in system
//
int procinfo_setup(vector<PROCINFO>& pi) {

#ifdef HAVE_DIRENT_H
    DIR *dir;
    dirent *piddir;
    FILE* fd;
    PROC_STAT ps;
    PROCINFO p;
    char pidpath[1024];
    char buf[1024];

    dir = opendir("/proc");
    if (!dir) return 0;

    while (1) {
        piddir = readdir(dir);
        if (piddir) {
            if (isdigit(piddir->d_name[0])) {
                sprintf(pidpath, "/proc/%s/stat", piddir->d_name);

                fd = fopen(pidpath, "r");
                if (fd) {
                    fgets(buf, sizeof(buf), fd);
                    ps.parse(buf);
                    fclose(fd);

                    p.id=ps.pid;
                    p.parentid=ps.ppid;
                    p.swap_size=ps.vsize;
                    // rss = pages, need bytes
                    // assumes page size = 4k
                    p.working_set_size = ps.rss * 4096.;
					// page faults: I/O + non I/O
					p.page_fault_count = ps.majflt + ps.minflt;
                    // times are in jiffies, need seconds
                    // assumes 100 jiffies per second
                    p.user_time = ps.utime / 100.;
                    p.kernel_time = ps.stime / 100.;
                    p.is_boinc_app = false;
                    pi.push_back(p);
                }
            }
        } else {
            closedir(dir);
            return 0;
        }
    }
 
#endif    
    return 0;

}

// Scan the process table adding in CPU time and mem usage.
// Loop thru entire table as the entries aren't in order.
// Recurse at most 4 times to get additional child processes 
//
void add_child_totals(PROCINFO& pi, vector<PROCINFO>& piv, int pid, int rlvl) {
    unsigned int i;

    if (rlvl > 3) {
        return;
    }
    for (i=0; i<piv.size(); i++) {
        PROCINFO& p = piv[i];
        if (p.parentid == pid) {
            pi.kernel_time += p.kernel_time;
            pi.user_time += p.user_time;

            // only count process with most swap and memory
            if (p.swap_size > pi.swap_size) {
                pi.swap_size = p.swap_size;
            }
            if (p.working_set_size > pi.working_set_size) {
                pi.working_set_size = p.working_set_size;
            }

            p.is_boinc_app = true;
            // look for child process of this one
            add_child_totals(pi, piv, p.id, rlvl+1); // recursion - woo hoo!
        }
    }
}

// fill in the given PROCINFO (which initially is zero except for id)
// with totals from that process and all its descendants
//
void procinfo_app(PROCINFO& pi, vector<PROCINFO>& piv) {
    unsigned int i;

    for (i=0; i<piv.size(); i++) {
        PROCINFO& p = piv[i];
        if (p.id == pi.id) {
            pi.kernel_time += p.kernel_time;
            pi.user_time += p.user_time;
            pi.swap_size += p.swap_size;
            pi.working_set_size += p.working_set_size;
            p.is_boinc_app = true;

            // look for child processes
            //
            add_child_totals(pi, piv, pi.id, 0);
            return;
        }
    }
}

void procinfo_other(PROCINFO& pi, vector<PROCINFO>& piv) {
    unsigned int i;

    memset(&pi, 0, sizeof(pi));
    for (i=0; i<piv.size(); i++) {
        PROCINFO& p = piv[i];
        if (!p.is_boinc_app) {
            pi.kernel_time += p.kernel_time;
            pi.user_time += p.user_time;
            pi.swap_size += p.swap_size;
            pi.working_set_size += p.working_set_size;
            p.is_boinc_app = true;
        }
    }
}